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Life, Unbounded

Life, Unbounded


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Astrobiology Roundup II

The views expressed are those of the author and are not necessarily those of Scientific American.


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Life in all it's glory... (Credit: C. Scharf)

It’s been a busy season for research that comes in under the astrobiology umbrella, here’s a smattering of some of the more interesting recent discoveries and studies.

 

 

 

The youngest solar system….so far.

A true baby - a dark disk of matter extends above and below in this image of L1527 IRS (Credit: Nature and Tobin et al. 2012)

Locating and studying the birth of stars and planets is an enormous challenge, but a vital component in learning about the pathways to systems like ours and the billions that must exist across the Milky Way.

Apart from being shrouded by light-absorbing gas and dust, baby solar systems change rapidly. To go from the glint in the eye of a core of condensing nebula to a star ready to fully fire up its nuclear engine takes the equivalent of 7 hours in human terms (100,000 years for a star like our Sun) compared to a total stellar lifetime. That’s a fast gestation. It also means that you have to be clever and lucky in order to catch one of these baby systems in its earliest stages.

A recent study by Tobin et al. published in Nature (preprint here) manages just that. Peering into a nascent system with millimeter and submillimeter wavelength telescopes they find what appears to be a 300,000 year old object. This proto-star has not yet finished accumulating all its eventual mass from a rain of interstellar material, but it already seems to be surrounded by a disk of matter about seven times the mass of Jupiter – fertile ground for new planets. This system, L1527 IRS, is about 460 light years from us in the Taurus cloud nebula and will be a fascinating and important reference point in the future.

The origin of life…as software?

Understanding the mechanics of life’s origins here on Earth has been vexing us for, well, for as long as you care to mention. Nonetheless in recent years a wealth of new insights have come from studying the complex behaviors of chemical systems, the multi-purpose functions of structures like proteins, and the possible combination of RNA and proteins to build ‘proto-life’. Somewhere in all of this may be clues to how ‘raw’ chemistry made a transition to what we’d consider ‘life’ – an admittedly somewhat ill-defined change, but it’s our current paradigm.

Now to add a new spin to all of this, Walker and Davies propose that more can be learned about this transition by considering the use of information – the software rather than the hardware of life. In essence they argue that the flow of information – stored data, signals and so on, can distinguish between abiotic chemical systems and biotic, ‘living’, systems. In other words, there should be a difference in the logic of a system, in its organization, that can point us to the actual chemistry involved.

It’s intriguing, although I personally find myself a little uncomfortable with the hints of vitalism in this way of thinking – that life is somehow truly distinct from other phenomena, not so much part of a continuum of processes and complexity. Time will tell where this all goes…

The hydrocarbon Nile

The river runs north (Credit: JPL/NASA/Caltech/ASI)

Finally, yet another astonishing discovery from the Cassini mission to Saturn (dollar-for-science probably one of the most cost-effective missions humans have ever built). This time it’s a high resolution radar map of Titan’s northern polar region that shows an extraordinary river system, replete with a delta-like outlet to a sea of liquid hydrocarbons.

The topography and geometry of this river (seen as a dark, non-radar-reflecting feature) suggests that it may in places be following a fault line on Titan’s surface – the equivalent of many terrestrial rivers and our boring silicate and carbonate planetary crust. Although the processes forming the fault are probably not the same as those from Earth’s plate tectonics.

Altogether this system spans about 200 miles, and the fluid of the river and northern sea is thought to be a mix of ethane and methane.

My only question is – are there crocodiles?

You can see the full map here.

 

 

Caleb A. Scharf About the Author: Caleb Scharf is the director of Columbia University's multidisciplinary Astrobiology Center. He has worked in the fields of observational cosmology, X-ray astronomy, and more recently exoplanetary science. His latest book is 'Gravity's Engines: How Bubble-Blowing Black Holes Rule Galaxies, Stars, and Life in the Cosmos', and he is working on 'The Copernicus Complex' (both from Scientific American / Farrar, Straus and Giroux.) Follow on Twitter @caleb_scharf.

The views expressed are those of the author and are not necessarily those of Scientific American.





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  1. 1. Bill_Crofut 6:59 pm 12/13/2012

    Dr. Scharf,

    Re: “Somewhere in all of this may be clues to how ‘raw’ chemistry made a transition to what we’d consider ‘life’–-an admittedly somewhat ill-defined change, but it’s our current paradigm.”

    One of the better known pioneers in the assertion of the chemical origin of life, though still an enthusiastic promoter,^ was also, seemingly, a realist:

    “The problem of the origin of life has turned out to be much more difficult than I, and most other people envisioned.”

    [Prof. Stanley L. Miller. 1991. In the Beginning... An interview by staff writer John Horgan. SCIENTIFIC AMERICAN, January, p. 117]

    ^ http://blogs.scientificamerican.com/cross-check/2012/07/29/stanley-miller-and-the-quest-to-understand-lifes-beginning/

    Link to this
  2. 2. Postman1 7:13 pm 12/16/2012

    Definitely a pyramid on the upper left bank, but I can’t find a sphinx. LOL! If we ever get that boat landed on Titan, I hope they sail it up this baby like Cleopatra’s Barge.

    Link to this
  3. 3. DaniEder 10:44 am 12/18/2012

    Alert the oil companies. There are rivers and lakes of natural gas on Titan. Earthly natural gas is 90% methane and 10% ethane.

    Link to this
  4. 4. Torbjörn Larsson, OM 8:54 am 01/14/2013

    I too find the vitalism disturbing. But not surprising, Davies is a deist and the Byeond Center is financed by at least two religious organisations, the Center for Theology and the Natural Sciences and the Templeton Foundation (through its front the Foundational Questions in Science Institute). [ http://beyond.asu.edu/sponsors ]

    We already know it is unnecessary to inject a qualitative difference in the transition process between chemical and biological evolution. According to thermodynamical models a population of RNA replicators can crystallize out during chemical evolution. Then that happens in liposomes produced by hydrothermal vent lipids, biological evolution takes over in Shoztak’s protocell fashion. Faster replicators promote liposome growth by their eating smaller protocells, et cetera.

    Link to this
  5. 5. Torbjörn Larsson, OM 8:59 am 01/14/2013

    @Bill Crofut: What is that supposed to mean? Quantum mechanics also turned out to be much more difficult than most people envisioned. Reversely, we have made much progress in astrobiology since Miller’s sentiment, showing that the area is fruitful and simple enough to proceed.

    Today we know many potential pathways for the process from chemical to biological evolution, enough that the work is to test which works and which doesn’t.

    Link to this

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